Query performance events
After 15m performance, bit errors occur in local station for the signals that are received from the opposite station and pass through 5 OLA stations. The channels that report bit errors and number of bit errors are not stable.
No bit error occurs on the signals sent from the opposite station to the local station.
Conclusion: Bit errors occur in one direction.
Check optical power.
Check the optical power of the amplifier at each station on the NMS. The optical power is identical with the value specified during engineering commissioning.
Check optical power of the LWF at the local station on the NMS. The optical power is identical with the value specified during engineering commissioning.
Adjust optical power:
Adjust the optical power. With OSNR guaranteed, increase the input optical power of the optical fiber with bit errors. Observe the variation of the number of bit errors on the NMS. It shows the number of bit errors increases with the optical power. Reduce the input optical power of the fiber. It shows that the number of bit errors decreases with the optical power.
Check the transmit power of the LWF board in slot 10 in the local station, which the transmission direction is from the opposite station to the local station. Trace step by step each site the OAU receiving power and transmit go to the local station also power gain. Make sure the power receive and power transmit adjust equally or difference is not significant.
The launched optical power of the upstream station is excessively high about +15 dBm and the OAU gain +28 dB.
The bit errors are caused by the non-linearity of optical fiber. Reduce the input optical power in the local station and bit error problem is solved.